CHARNOCK or CHERNOCK, ROBERT (1663?–1696), vice-president of Magdalen College, Oxford, and Jacobite conspirator, born about 1663, was the son of Robert Chernock of the county of Warwick, and matriculated at Magdalen College, Oxford, 27 May 1680. He proceeded B.A. on 4 Feb. 1682–3 and M.A. on 26 Oct. 1686. In 1686 he was elected fellow of his college by royal mandate, and soon afterwards declared himself a Roman catholic. That Charnock became a priest about the same time is proved by the fact that on 25 Sept. in the following year he assisted in the celebration of mass and of other rites in the chantry of St. Amand in the parish of East Hendred, Buckinghamshire.

On the death (24 March 1686–7) of the president of Magdalen, Dr. Henry Clarke, Charnock vigorously aided James II in his attempt to force on the college a president of his own choosing. He delivered (11 April 1687) to Dr. Charles Aldworth, the vice-president, the royal mandate directing the fellows to appoint Anthony Farmer, whose academic standing and scandalous life legally disqualified him for the post; and he opposed the suggestion of his colleagues to defer the election till the king had answered their petition praying for a free exercise of their rights. On 15 April, when a college meeting was held and John Hough was elected president by the fellows, Charnock alone abstained from taking the sacrament, and persisted, with one other fellow, in declaring for Farmer. After the king had abandoned Far- mer's claim and put up a new nominee, Samuel Parker, bishop of Oxford, Charnock wholly separated himself from his colleagues, supported the ecclesiastical commission sent to Oxford to punish the fellows' insubordination, and on 25 Oct. was present when Parker's proxy and chaplain, William Wickens, was installed, after a forced entrance, in the president's lodgings. On 16 Nov. all the fellows, except Charnock, whose ‘dutiful’ conduct was commended by the authorities, were expelled on refusing to make full submission and retractation; the college was filled with Roman catholic nominees, and the Roman communion definitely adopted. Charnock assumed the office of dean, and took part in disgraceful wrangles in the hall with the demies who espoused the cause of the exiles. On 11 Jan. 1687–8 a royal mandate constituted him vice-president of Magdalen, and six days later he expelled fourteen demies. The Bishop of Oxford, the president, died on 21 March, and on 31 March Charnock admitted in his place, under orders from the crown, Bonaventura Gifford, the Roman catholic bishop of Madaura. In the following October the failure of the trial of the seven bishops opened James II's eyes to his errors, and he entrusted the Bishop of Winchester with the task of restoring Magdalen to its old condition. On 25 Oct. Charnock was expelled.

Little is known of Charnock for seven years after his departure from Oxford. He apparently soon made his way to James II's court at St. Germains, and his enthusiasm for the Jacobite cause led him to adopt the desperate device of attempting the assassination of William III. After 1692 he was frequently in England negotiating the conspiracy, and in 1695 had lodgings in Norfolk Street, Strand, with another Jacobite, Captain Porter. There Sir George Barclay [q. v.] sought him out early in 1696 and gave him a commission from James II, the terms of which are much disputed, to assist in a rising against William in which the exiled king and a French army were to take part. Charnock confessed later that the assassination, or at any rate the seizure of the person, of William III was in his eyes a necessary preliminary to the success of the plot. He accordingly arranged with Barclay and a few intimate friends, at meetings held at his lodgings and at taverns in the neighbourhood, to collect forty men, eight of whom he was to supply himself, for the purpose of stopping and killing William near Turnham Green one Saturday on the king's return from hunting in Richmond Park. Charnock had all prepared for the attempt on Saturday, 15 Feb. 1695–6, and on the same day in the following week, but on both days William stayed in London, and on the latter day Charnock, with several of the conspirators, was suddenly arrested. Charnock, with two associates, Edward King and Thomas Keyes, was tried at the Old Bailey on 11 March; his friend Porter turned king's evidence. The prosecuting counsel spoke of him as ‘Captain’ Charnock, which suggests that he had abandoned his clerical orders and had received a titular commission in the French army. At the trial Charnock showed great presence of mind, temper, and judgment, and confined his defence to a searching examination of the evidence adduced by the crown. The jury, however, found him guilty of compassing the king's death; capital sentence was passed, and he was drawn, hanged, and quartered at Tyburn on 18 March 1695–6. On the scaffold he handed a paper to the sheriff in which he acknowledged his guilt, but exculpated James II and the English Roman catholics from any share in the conspiracy. This paper was published in French and Dutch translations. In another paper still unpublished, and now lying in manuscript among the Nairne MSS. at the Bodleian, Charnock defends himself at greater length, compares himself to Mucius Scævola, and denies that the killing of a monster of iniquity like William is otherwise than an honourable act which would merit the approval of James II and all right-minded men. Mr. Vernon, writing of the trial to Lord Lexington (13 March 1695–6), describes Charnock's undaunted demeanour, and adds: ‘His conversation was easy, generous, and insinuating, and one that even made his pleasures and debaucheries subservient to his ends. He is but of indifferent extraction, and therefore his practising could be but among an inferior rank of people, or else he might have been another Catiline’ (Lexington Papers, 187). Burnet gives two accounts of Charnock's behaviour while in prison under sentence. According to the first, Charnock's brother was sent to the prison to entreat the prisoner, under promise of relaxation of punishment, to make a full confession of his recent conduct, but Charnock declined the invitation on the ground that his confession would jeopardise the lives of too many of his friends. Lord Somers told Burnet, on the other hand, that Charnock offered a full confession to William III in exchange for a commutation of his sentence to an ‘easy’ imprisonment for life, and that William refused it on hearing that it would implicate so many persons as to disturb all sense of public security. A letter in the Public Record Office, written by Charnock shortly before his death, insists with such obvious sincerity on the justice of his cause that we are inclined to accept Burnet’s first account as the true one.